Domain flipping is a popular online business model where you purchase domain names with potential resale value, hoping to sell them later at a profit. Look for short, memorable, or niche-specific domains that might attract businesses in a growing industry. Use platforms like GoDaddy Auctions, Flippa, or Sedo to buy and list domains. Research keyword trends to target valuable names, and consider holding onto domains that may increase in value. Building a portfolio of profitable domains can lead to steady income over time, especially as you gain experience and understand the market’s demand for specific types of domains.